CuO@NiCoFe-S core-shell nanorod arrays based on Cu foam for high performance energy storage

Growing electroactive materials directly on a three-dimensional conductive substrate can effectively reduce the "ineffective area" of the electrode during the electrochemical reaction, increase the utilization rate of the material, and thus increase the energy density of the device. Using the network structure of the three-dimensional conductive substrate to design electrode materials with unique microstructures can also improve the stability of the materials. In this work, we obtained different copper-based materials on the copper foam (CF) by in-situ growth method, and designed an independent three-dimensional layered CuO@NiCoFe-S (CuO@NCFS) core-shell nanostructure composite material. CuO@NCFS exhibits excellent electrochemical performance, reaching a specific capacitance of 4551 mF cm^-2 at a current density of 1 mA cm^-2 with good cycle stability (94.2% after 5000 cycles). In addition, the asymmetric supercapacitor (ASC) uses CuO@NCFS as the positive electrode and rGO as the negative electrode, which can provide an energy rate density of 4.5 mW cm^-2 at a high energy density of 99.9 μWh cm^-2. The findings provide some insight into rational design of electrode materials for high performance energy storage.